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authorwdenk <wdenk>2004-01-24 20:25:54 +0000
committerwdenk <wdenk>2004-01-24 20:25:54 +0000
commitc178d3da6f1ac765cd880530a0672540b415a01c (patch)
tree67e3b8e9a791d2ec97798239b5abba15e0cb5aaf /cpu/mpc8xx/plprcr_write.S
parentef978730dcb3e7e398fe9b57633f3f67260c1bbc (diff)
* Add variable CPU clock for MPC859/866 systems (so far only TQM866M):
see doc/README.MPC866 for details; implement workaround for "SIU4" and "SIU9" silicon bugs on MPC866; calculate CPU clock frequency from PLL register values. * Add support for 128 MB RAM on TQM8xxL/M modules
Diffstat (limited to 'cpu/mpc8xx/plprcr_write.S')
-rw-r--r--cpu/mpc8xx/plprcr_write.S145
1 files changed, 145 insertions, 0 deletions
diff --git a/cpu/mpc8xx/plprcr_write.S b/cpu/mpc8xx/plprcr_write.S
new file mode 100644
index 00000000000..7d39a0edf6c
--- /dev/null
+++ b/cpu/mpc8xx/plprcr_write.S
@@ -0,0 +1,145 @@
+/*
+ * (C) Copyright 2004
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <mpc8xx.h>
+#include <ppc_asm.tmpl>
+#include <asm/cache.h>
+
+#define CACHE_CMD_ENABLE 0x02000000
+#define CACHE_CMD_DISABLE 0x04000000
+#define CACHE_CMD_LOAD_LOCK 0x06000000
+#define CACHE_CMD_UNLOCK_LINE 0x08000000
+#define CACHE_CMD_UNLOCK_ALL 0x0A000000
+#define CACHE_CMD_INVALIDATE 0x0C000000
+#define SPEED_PLPRCR_WAIT_5CYC 150
+#define _CACHE_ALIGN_SIZE 16
+
+
+ .text
+ .align 2
+ .globl plprcr_write_866
+
+/*
+ * void plprcr_write_866 (long plprcr)
+ * Write PLPRCR, including workaround for device errata SIU4 and SIU9.
+ */
+
+plprcr_write_866:
+ mfspr r10, LR /* save the Link Register value */
+
+ /* turn instruction cache on (no MMU required for instructions)
+ */
+ lis r4, CACHE_CMD_ENABLE@h
+ ori r4, r4, CACHE_CMD_ENABLE@l
+ mtspr IC_CST, r4
+ isync
+
+ /* clear IC_CST error bits
+ */
+ mfspr r4, IC_CST
+
+ bl plprcr_here
+
+plprcr_here:
+ mflr r5
+
+ /* calculate relocation offset
+ */
+ lis r4, plprcr_here@h
+ ori r4, r4, plprcr_here@l
+ sub r5, r5, r4
+
+ /* calculate first address of this function
+ */
+ lis r6, plprcr_write_866@h
+ ori r6, r6, plprcr_write_866@l
+ add r6, r6, r5
+
+ /* calculate end address of this function
+ */
+ lis r7, plprcr_end@h
+ ori r7, r7, plprcr_end@l
+ add r7, r7, r5
+
+ /* load and lock code addresses
+ */
+ mr r5, r6
+
+plprcr_loop:
+ mtspr IC_ADR, r5
+ addi r5, r5, _CACHE_ALIGN_SIZE /* increment by one line */
+
+ lis r4, CACHE_CMD_LOAD_LOCK@h
+ ori r4, r4, CACHE_CMD_LOAD_LOCK@l
+ mtspr IC_CST, r4
+ isync
+
+ cmpw r5, r7
+ blt plprcr_loop
+
+ /* IC_CST error bits not evaluated
+ */
+
+ /* switch PLPRCR
+ */
+ mfspr r4, IMMR /* read IMMR */
+ rlwinm r4, r4, 0, 0, 15 /* only high 16 bits count */
+
+ /* write sequence according to MPC866 Errata
+ */
+ stw r3, PLPRCR(r4)
+ isync
+
+ lis r3, SPEED_PLPRCR_WAIT_5CYC@h
+ ori r3, r3, SPEED_PLPRCR_WAIT_5CYC@l
+
+plprcr_wait:
+ cmpwi r3, 0
+ beq plprcr_wait_end
+ nop
+ subi r3, r3, 1
+ b plprcr_wait
+
+plprcr_wait_end:
+
+ /* turn instruction cache off
+ */
+ lis r4, CACHE_CMD_UNLOCK_ALL@h
+ ori r4, r4, CACHE_CMD_UNLOCK_ALL@l
+ mtspr IC_CST, r4
+ isync
+
+ lis r4, CACHE_CMD_INVALIDATE@h
+ ori r4, r4, CACHE_CMD_INVALIDATE@l
+ mtspr IC_CST, r4
+ isync
+
+ lis r4, CACHE_CMD_DISABLE@h
+ ori r4, r4, CACHE_CMD_DISABLE@l
+ mtspr IC_CST, r4
+ isync
+
+ mtspr LR, r10 /* restore original Link Register value */
+ blr
+
+plprcr_end: